Snapped my 4x4x2 Output Shaft Tonight

[5001craig]

I installed a used 4x4x2 box about a year and a half ago and tonight I drove it to a buddy's house to give him a ride and when we pulled out of his drive I had no steering. The output shaft of the steering box broke. And my EB is sitting at his house for the night--outside--and it's supposed to rain... Actually it's raining now.

So my questions are:

Is this a freak thing that won't happen again with a new stock shaft?

And if not, is there an upgrade to the output shaft? Something like 400M or?​

This is kind or a critical part IMO.

I've searched the forum and don't see anything like this--just threads about rebuilds. I don't have a problem with sending the box somewhere to be rebuilt (probably would be a good idea--PSC seems like a good option) as well as hopefully get an upgraded output shaft. My thought is that they make upgraded output shafts for other items on trucks so why not the steering box?

For the record, I'm running about 5 psi in load range E Super Swampers and this probably didn't help at all. The shaft looked like it was partially broke for some time as there was some rust on part of the shaft where it broke. Just glad it didn't let go on the road. It seems to handle better at lower tire pressure. I don't drive it much on the road.

Running a BC Broncos frame reinforcement kit and the box is tight on the frame. TRU with WH Track Bar Riser Bracket and angles don't seem to be bad to me.

Any help would be greatly appreciated. Thanks in advance.

Craig

 

[broncosbybart]

I'll probably get flamed for this but I don't think the 4x4x2 box is as strong as its hyped to be. Seen plenty of failed or cracked sector shafts. My advice is a hydro assist setup. It takes a lot of load off the box.

 

[spap]

I'm just glad it broke on you in the driveway and not actually driving it
That would have sucked

 

[Rustytruck]

These steering boxes are aproaching 30 years old and used on big heavy 4wd trucks when big oversize tires were the norm. Im sure there are a whole lot of abused boxes out there. I have personally seen 2 cracked sector shafts in used boxes. The 2 shafts i saw were diagonal cracks in the center main body of the shaft. You cant see it without pulling the shaft. If you are really concerned might want to have the replacement shaft magnafluxed.

 

[TN1776]

I've seen them crack too, I'm not sold on them being the end all be all of bronco steering. As was said they're old boxes. Having a shop rebuild it as well as inspect and Magna flux the replacement sector shaft would be best.

I'm not sure that we have many more options besides full hydro, or ram assisted steering ar this point, old rigs like it or not are a declining market and it's tough to get a vendor to invest in new designs for them.

 

[Nobody]

These boxes were great because of the availability and convenience in their day, not because of strength. Broken sector shafts are not common, but not uncommon either. Fix it or get another one, then eliminate the drop pitman arm. It shouldn't be there.

 

[Broncobowsher]

Don't know of any extra strong material upgrades.
Weakness is the diameter of the sector shaft. As long as everyone want to keep using original Bronco sized pitman arms we are stuck with that diameter. It is pretty much the standard size sector shaft for so much stuff. Even if something was a bit stronger there is still the issue of the strength of the steering box and the frame rail itself. Those have also failed in the past.

I know of one small steering box with a larger diameter sector shaft, the Nissan Xterra box. But you run into the issue of finding a pitman arm that fits them. I salvaged a Cal-mini pitman arm to get one with enough throw and was stout. But that is just the sector shaft that is stouter.

Ram assist. That takes a huge amount of forces out of the steering box. Instead of the power assist trying to twist the sector shaft and trying to rip the steering box off the frame rail you move half or so of the power steering forces into the ram and it's attachment points.

 

[hucklburry rev2]

Like was said, and they are usually sourced from junkyard trucks - they lead a hard lift, became beaters towards the end, people run really big tires, kids driving them hard (I never did that), or maybe from wrecked trucks.

But I have one, and since I need to seal it when I install it, and we have a kit at work, I think I will check mine before installing (someday).

 

[5001craig]

Thanks for the feedback guys. I got her home today and after looking at the shaft, it is evident that it's been cracked for quite a while. The shaft is supposed to be solid, right? The break looks weird to me as it was attached (until last night) pretty evenly around the outside.

Now I'm off to researching ram assist.

 

[mlogan24]

BC Broncos mentioned on their site that they cryo'd the 4x4x2 sector shaft on their Baja truck.

 

[70_Steve]

I may be wrong, but that shaft looks like it was broken and welded. Why else would there be a pin in the middle of the shaft? Turn the pieces on a lathe to drill the centering hole, weld the shaft, turn again to remove the excess weld.

You did say you bought it used...

 

[sykanr0ng]

Some Ford steering boxes do not have a bearing supporting the lower sector shaft only the seal 'supporting' it.
This is why those boxes get torn up there, when the seal wears against the shaft.

I have read that Redhead Steering Gears offered adding a bearing as a service, I don't know if they still do.

 

[5001craig]

I may be wrong, but that shaft looks like it was broken and welded. Why else would there be a pin in the middle of the shaft? Turn the pieces on a lathe to drill the centering hole, weld the shaft, turn again to remove the excess weld.

You did say you bought it used...

Yep bought it used. Not sure why I didn't think about it being welded up after breaking. Makes total sense now. Thanks.

Some Ford steering boxes do not have a bearing supporting the lower sector shaft only the seal 'supporting' it.
This is why those boxes get torn up there, when the seal wears against the shaft.

I have read that Redhead Steering Gears offered adding a bearing as a service, I don't know if they still do.

I checked-out Redhead Steering Gears. They look like they know what they're doing.

I'm thinking the permanent fix to my solution is to go TRO (Extreme Custom Fab & Parts tie rod contacts my Ruff Stuff diff cover and I think the 3" raise of the tie rod will fix this), measure tie rod stroke, get a new box or have mine rebuilt and go with ram assist in that order. Will be making some calls in the morning. Not really sure what the differences between this kit and this kit from PSC are and will be asking them tomorrow. Obviously, the first kit includes a new box but it also has a lot more parts in it. Need to do more research.

Thanks for the replies and help.

 

[naneumranch]

Check with west Texas off-road for ram assist and rebuild.

http://westtexasoffroad.wixsite.com/wtor
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[chrlsful]

west tx has been our go-to for yrs...

 

[5001craig]

I made some calls today and got a bit of an education.

I had no idea these 4x4x2 boxes are so rare. Made for two years only. With a broken sector shaft I pay the core ($300). Guess I should pick up a spare when I see one for sale at a reasonable price.

Mine's packed-up and going to get rebuilt tomorrow. Getting a ram assist also. Damn that thing is harder to remove with the body on...

 

[sykanr0ng]

I made some calls today and got a bit of an education.

I had no idea these 4x4x2 boxes are so rare. Made for two years only. With a broken sector shaft I pay the core ($300). Guess I should pick up a spare when I see one for sale at a reasonable price.

Mine's packed-up and going to get rebuilt tomorrow. Getting a ram assist also. Damn that thing is harder to remove with the body on...

Not quite as rare as that; 78-79 Bronco or 76-79 F150 4X4 are all though and they also work on some F series to convert them to power steering.

There are at least three for sale in the classifieds here:

http://classicbroncos.com/forums/showthread.php?t=269503

http://classicbroncos.com/forums/showthread.php?t=264990

http://classicbroncos.com/forums/showthread.php?t=268672

Another already converted:

http://classicbroncos.com/forums/showthread.php?t=263589

 

[5001craig]

Not quite as rare as that; 78-79 Bronco or 76-79 F150 4X4 are all though and they also work on some F series to convert them to power steering.

There are at least three for sale in the classifieds here:

http://classicbroncos.com/forums/showthread.php?t=269503

http://classicbroncos.com/forums/showthread.php?t=264990

http://classicbroncos.com/forums/showthread.php?t=268672

Another already converted:

http://classicbroncos.com/forums/showthread.php?t=263589

Thanks for the reply.

My experience was I purchased one converted and it had a broke/welded sector shaft. Maybe I'm just a little gun-shy to buy another that might be the same shape. I'm going with one from the big shops that magnaflux the shafts.

 

[englewoodcowboy]

Looking at your setup, I agree with Nobody, lose the drop pitman arm since you went with a trac bar riser on the axle, you need to switch to TRO and your geometry would then be correct by looking at it. I also agree, it looks like it broke before and was pinned and welded...


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[DirtDonk]

One thing to look for if going back with a used one is the stock shafts were often starting to twist visibly (spiral splines) just above the pitman arm. This could have been due to an accident (junkyard trucks especially of course) or just abuse with big tires.
Seen a lot of those.

If changing the sector shaft anyway, this is not an issue, but if you score a good one there's not much need to change the shaft anyway. So best to start with a good one.

Paul